Does lower the level of greenhouse gases, the more heat is retained and returned to earth, causing an increase in global temperatures?

The statement that lower the level of greenhouse gases, the more heat is retained and returned to Earth, causing an increase in global temperatures is false. 
The term greenhouse effect is caused by greenhouse gases in our atmosphere . These greenhouse gasses trap and redirect the heat back to Earth, which results in increased temperatures and contributes to global warming. So, in contrast the that lower the level of greenhouse gases, the less heat is retained and returned to Earth, causing an decrease in global temperatures.

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen